EP 43: Progesterone During Pregnancy

When you think of progesterone think “pro gestation”, it's the pregnancy hormone that establishes and supports a pregnancy by assisting in egg implantation. Prior to egg implantation progesterone helps to thicken the uterine lining.

Where does it come from:

In early pregnancy progesterone comes from the corpus luteum (CL), which is a cyst on the ovaries formed from the follicles. The CL produces progesterone for 10 weeks and then the placenta forms and takes over.

In a normal cycle without pregnancy occurring your progesterone would increase around ovulation, then decrease as your uterine lining sheds and you menstruate 12-14 days after ovulation.

How to know if you have low progesterone:

- Irregular or absent menstrual cycle

- Recurrent miscarriage

- Other hormonal imbalance symptoms: mood swings, high estrogen, weight gain, PMS

GET TESTED: the gold standard to test your progesterone is on day 21of your cycle. Normal level depends on age, but in general on day 21 you want it >10 ng/ml.

When to supplement progesterone:

1. IVF or fertility treatments- you will almost always be started on a progesterone supplement

2. Recurrent miscarriage- done with your doctor / midwife

3. You tested with low progesterone

How to supplement: usually only up to 12 weeks of pregnancy

  1. Vaginal suppositories- Widely used, Wax-based, Compounded by specialty pharmacies, Used up to 1-3 times a day, leakage can be messy.

  2. Vaginal gel- used once a day for progesterone supplementation. Some discharge reported during use.

  3. Vaginal inserts- FDA-approved for progesterone supplementation but not for progesterone replacement, Effective in women under 35 years, used 2 to 3 times a day.

  4. Injections- Widely used; the oldest, most established method for progesterone supplementation. injected into the butt once a day, Requires a long, thick needle to penetrate layers of fat and skin. Injections may be painful and difficult to administer by yourself

  5. Over the counter cream- made from wild yam , NO PROGESTERONE IN, has a compound in it that can be converted into progesterone in a lab but not the human body.

Side effects-

  • Drowsiness

  • Fluid retention or bloating

  • Hot flashes

  • Depression

  • Vaginal discharge

  • Urinary problems

  • Dizziness

  • Abdominal pain or cramping

  • Headaches

  • Breast tenderness

  • Joint pain


Overall the use of progesterone for the treatment of recurrent miscarriages showed no statistically significant difference in miscarriage rates. The method of administration also showed no statistically significant difference.

1. Only one study compared vaginally administered progestagens with placebo, a second one comparing it with no treatment. The incidence of recurrent miscarriage was similar in both groups.


2. 4000 women with bleeding during first trimester, 50% given progesterone supplementation and 50% given a placebo. Among women with bleeding in early pregnancy, progesterone therapy administered during the first trimester did not result in a significantly higher incidence of live births than placebo.